Various small fixes

Author: tkrotoff

README.md

@@ -380,10 +380,7 @@ module.exports = {
     ],
     '@babel/preset-react'
   ],
-  plugins: [
-    '@babel/plugin-proposal-class-properties',
-    '@babel/plugin-proposal-object-rest-spread'
-  ]
+  plugins: []
 };
 ```
 

examples/Bootstrap4/webpack.config.js

@@ -1,7 +1,6 @@
 // @ts-check
 
 const path = require('path');
-const postcssPresetEnv = require('postcss-preset-env');
 
 /** @type import('webpack').Configuration */
 const config = {

packages/react-form-with-constraints/jest.setup.ts

@@ -7,6 +7,8 @@ configure({ adapter: new Adapter() });
 // [console.assert not throwing with v22.4.0](https://github.com/facebook/jest/issues/5634)
 console.assert = assert;
 
+// FIXME Remove when Node.js >= 15 is LTS
+//
 // [Event: 'unhandledRejection'](https://nodejs.org/api/process.html#process_event_unhandledrejection)
 // [Bluebird Error management configuration](http://bluebirdjs.com/docs/api/error-management-configuration.html)
 //

packages/react-form-with-constraints/src/Nullable.ts

@@ -1,4 +1,6 @@
 /**
  * Make all properties in T nullable
+ *
+ * https://github.com/microsoft/TypeScript/blob/v4.0.5/src/lib/es5.d.ts#L1439-L1441
  */
 export type Nullable<T> = { [P in keyof T]: T[P] | null };